Ground fault circuit interrupter (GFCIs) are circuits that are designed to interrupt power to various loads, such as household appliances, consumer electrical products and branch circuits when the occurrence of a ground fault is detected. Many of these various loads or electrical wiring devices include a line side, which is connectable to a source of electrical power. In addition, these devices have a load side, which is connectable to one or more loads. At least one conductive path exists between the line and load sides. Specifically, when abnormal current flows through a line to ground, the GFCI immediately interrupts the fault to halt this abnormal flow.
GFCI devices, such as the device described in commonly owned U.S. Pat. No. 4,595,894, incorporated herein by reference, use a trip mechanism to break an electrical connection between the line side and the load side. Such devices are resettable after they are tripped by, for example, the detection of a ground fault. Specifically, in the '894 patent, the trip mechanism used to cause the breaking of the circuit (i.e., the conductive path between the line and load sides) includes a solenoid (or trip coil). Once an imbalance in current flow is detected between the power lines, the GFCI produces an output signal. The output signal energizes a trip coil within the trip mechanism which disconnects the source of electrical power from a load.
The conventional GFCI further includes a triode alternating current switch (TRIAC) which controls the amount of current flow when properly activated. Instances, however, may arise where the TRIAC becomes shorted which causes the trip coil to be continuously energized. As a result, when the trip coil is continuously energized, it may become permanently damaged after a short period of time. Thereby, the trip mechanism will be disabled.
Accordingly, a user may find a GFCI in a tripped state and not be aware that the internal trip mechanism is not functioning properly. The user may then press the reset button, which will cause the device with an inoperative trip mechanism to be reset. Thus, a dangerous condition will exist wherein the GFCI will then provide power to a load without ground fault protection.
Accordingly, there is a need for providing an indication of such a GFCI failure condition.
The present invention is directed to overcoming, or at least reducing the effects of one or more of the problems set forth above.